The Synthesis of N-(Pyridylamino)tetrahydroisoquinolines and Benzazepines via The Pictet-Spengler Cyclization - Merriman, Gregory H; Fink, David M; Freed, Brian S; Kurys, Barbara E; Pavlek, Shelly; Varriano, Jennifer; Paulus, Erich F (Synlett, 2000)